Working medium and heat cycle system

ABSTRACT

A working medium for heat cycle comprising 1-chloro-2,3,3,3-tetrafluoropropene is employed for a heat cycle system (such as a Rankine cycle system, a heat pump cycle system, a refrigerating cycle system 10 or a heat transport system).

This application is a continuation of U.S. application Ser. No.14/084,016, filed Nov. 19, 2013, now U.S. Pat. No. 9,593,274; which is acontinuation of PCT Application No. PCT/JP2012/062842, filed on May 18,2012, which is based upon and claims the benefit of priority fromJapanese Patent Application No. 2011-112415 filed on May 19, 2011. Thecontents of those applications are incorporated herein by reference inits entirety.

TECHNICAL FIELD

The present invention relates to a working medium and a heat cyclesystem employing the working medium.

BACKGROUND ART

Heretofore, as a working medium for heat cycle such as a coolant for arefrigerator, a coolant for an air conditioner, a working fluid forpower generation system (such as exhaust heat recovery powergeneration), a working medium for a latent heat transport apparatus(such as a heat pipe) or a secondary cooling medium, achlorofluorocarbon (CFC) such as chlorotrifluoromethane ordichlorodifluoromethane or a hydrochlorofluorocarbon (HCFC) such aschlorodifluoromethane has been used.

However, influences of CFCs and HCFCs over the ozone layer in thestratosphere have been pointed out, and their use are regulated atpresent.

Accordingly, as a working medium for heat cycle, a hydrofluorocarbon(HFC) which has less influence over the ozone layer, such asdifluoromethane (HFC-32), tetrafluoroethane or pentafluoroethane, hasbeen used. However, it is pointed out that HFCs may cause globalwarming. Accordingly, development of a working medium for heat cyclewhich has less influence over the ozone layer and has a low globalwarming potential is an urgent need.

For example, 1,1,1,2-tetrafluoroethane (HFC-134a) used as a coolant foran automobile air conditioner has a global warming potential so high as1,430 (100 years). Further, in an automobile air conditioner, thecoolant is highly likely to leak out to the air e.g. from a connectionhose or a bearing.

As a coolant which replaces HFC-134a, carbon dioxide and1,1-difluoroethane (HFC-152a) having a global warming potential of 124(100 years) which is low as compared with HFC-134a, have been studied.

However, with carbon dioxide, the equipment pressure tends to beextremely high as compared with HFC-134a, and accordingly there are manyproblems to be solved in application to all the automobiles. HFC-152ahas a range of inflammability, and has a problem for securing thesafety.

As a working medium for heat cycle, of which combustibility issuppressed, which has less influence over the ozone layer and has lessinfluence over global warming, a hydrochlorofluoroolefin (HCFO) such ashydrochlorofluoropropene or a chlorofluoroolefin (CFO), having a highproportion of halogen which suppresses combustibility and having acarbon-carbon double bond which is easily decomposed by OH radicals inthe air, is conceivable.

As the hydrochlorofluoropropene, for example,1-chloro-3,3,3-trifluoropropene (E) (HCFO-1233zd(E)) has been known(Patent Document 1).

However, in a case where HCFO-1233zd(E) is used as a working medium forheat cycle, it is insufficient in the cycle performance (capacity).

PRIOR ART DOCUMENTS

Patent Documents

Patent Document 1: WO2010/077898

DISCLOSURE OF INVENTION

Technical Problem

The present invention provides a working medium for heat cycle, of whichcombustibility is suppressed, which has less influence over the ozonelayer, which has less influence over global warming and which provides aheat cycle system excellent in the cycle performance (efficiency andcapacity), and a heat cycle system, of which the safety is secured, andwhich is excellent in the cycle performance (efficiency and capacity).

Solution to Problem

The present invention provides a working medium for heat cycle(hereinafter sometimes referred to as working medium), which comprises1-chloro-2,3,3,3-tetrafluoropropene (hereinafter sometimes referred toas HCFO-1224yd).

The working medium of the present invention preferably further containsa hydrocarbon.

The working medium of the present invention preferably further containsa HFC.

The working medium of the present invention preferably further containsa hydrofluoroolefin (HFO).

The heat cycle system of the present invention employs the workingmedium of the present invention.

Advantageous Effects of Invention

The working medium of the present invention, which comprises HCFO-1224ydhaving a high proportion of halogen, has combustibility suppressed.Further, since it comprises HCFO-1224yd having a carbon-carbon doublebond which is easily decomposed by OH radicals in the air, it has lessinfluence over the ozone layer and has less influence over globalwarming. Further, since it comprises HCFO-1224yd, it provides a heatcycle system which is excellent in the cycle performance (efficiency andcapacity).

The heat cycle system of the present invention, which employs theworking medium of the present invention of which combustibility issuppressed, has safety secured.

Further, since it employs the working medium of the present inventionexcellent in the thermodynamic properties, it is excellent in the cycleperformance (efficiency and capacity). Further, due to excellentefficiency, a reduction in the power consumption will be attained, anddue to excellent capacity, downsizing of a system can be achieved.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a schematic construction view illustrating an example of arefrigerating cycle system.

FIG. 2 is a cycle diagram illustrating the state change of a workingmedium in a refrigerating cycle system on a temperature-entropy chart.

FIG. 3 is a cycle diagram illustrating the state change of a workingmedium in a refrigerating cycle system on a pressure-enthalpy chart.

DESCRIPTION OF EMBODIMENTS

<Working Medium>

The working medium of the present invention comprises1-chloro-2,3,3,3-tetrafluoropropene.

The working medium of the present invention may contain, as the caserequires, another working medium which will be gasified or liquefiedtogether with CFO1224yd, such as a hydrocarbon, a HFC, or a HFO.Further, the working medium of the present invention may be used incombination with a component other than the working medium, usedtogether with the working medium (hereinafter, a composition containingthe working medium and a component other than the working medium will bereferred to as a working medium-containing composition). The componentother than the working medium may, for example, be a lubricating oil, astabilizer, a leak detecting substance, a desiccating agent or otheradditives.

The content of HCFO-1224yd is preferably at least 60 mass %, morepreferably at least 70 mass %, further preferably at least 80 mass %,particularly preferably 100 mass % in the working medium (100 mass %).

(Hydrocarbon)

The hydrocarbon is a working medium component which improves solubilityof the working medium in a mineral lubricating oil.

The hydrocarbon has preferably from 2 to 5 carbon atoms, and may belinear or branched.

The hydrocarbon is specifically preferably propane, propylene,cyclopropane, butane, isobutane, pentane or isopentane, particularlypreferably propane, butane or isobutane.

The hydrocarbons may be used alone or in combination of two or more.

The content of the hydrocarbon is preferably from 1 to 40 mass %, morepreferably from 2 to 10 mass %, in the working medium (100 mass %). Whenthe content of the hydrocarbon is at least 1 mass %, the solubility ofthe lubricating oil in the working medium will sufficiently be improved.When the content of the hydrocarbon is at most 40 mass %, an effect tosuppress combustibility of the working medium will be obtained.

(HFC)

The HFC is a working medium component which improves the cycleperformance (capacity) of a heat cycle system.

The HFC is preferably a HFC which has less influence over the ozonelayer and which has less influence over global warming.

The HFC has preferably from 1 to 5 carbon atoms, and may be linear orbranched.

The HFC may, for example, be specifically difluoromethane,difluoroethane, trifluoroethane, tetrafluoroethane, pentafluoroethane,pentafluoropropane, hexafluoropropane, heptafluoropropane,pentafluorobutane or heptafluorocyclopentane. Among them, particularlypreferred is difluoromethane (HFC-32), 1,1-difluoroethane (HFC-152a),1,1,2,2-tetrafluoroethane (HFC-134), 1,1,1,2-tetrafluoroethane(HFC-134a) or pentafluoroethane (HFC-125), which has less influence overthe ozone layer and which has less influence over global warming.

HFCs may be used alone or in combination of two more.

The content of the HFC in the working medium (100 mass %) is preferablyfrom 1 to 99 mass %, more preferably from 1 to 40 mass %. For example,in a case where the HFC is HFC-134a, the refrigerating capacity will beimproved without a remarkable decrease of the coefficient ofperformance, within a content range of from 1 to 99 mass %. In the caseof HFC-245fa, the coefficient of performance and the refrigeratingcapacity will be improved within a content range of from 1 to 40 mass %.In the case of HFC-125, the refrigerating capacity will remarkably beimproved without a remarkable decrease of the coefficient ofperformance, within a content range of from 1 to 40 mass %. In the caseof HFC-32, the refrigerating capacity will remarkably be improvedwithout a decrease of the coefficient of performance, within a contentrange of from 1 to 20 mass %. In the case of HFC-152a, the refrigeratingcapacity will remarkably be improved without a decrease of thecoefficient of performance, within a content range of from 1 to 99 mass%. The HFC content can be controlled depending upon the requiredproperties of the working medium.

(HFO)

The HFO is a working medium component which improves the cycleperformance (capacity) of a heat cycle system.

As the HFO, preferred is a HFO which has less influence over the ozonelayer and which has less influence over global warming.

The HFO has preferably from 2 to 5 carbon atoms, and may be linear orbranched.

The FIFO may, for example, be specifically difluoroethylene,trifluoroethylene, trifluoropropylene, tetrafluoropropylene orpentafluoropropylene. Among them, particularly preferred is1,1-difluoroethylene (HFO-1132a), 1,2-difluoroethylene (HFO-1132) or1,1,2-trifluoroethylene (HFO-1123), which has less influence over theozone layer and which has less influence over global warming.

As HFO-1132, E isomer and Z isomer are present, and either of them maybe used, or a mixture thereof may be used.

The HFOs may be used alone or in combination of two or more.

The content of the HFO is preferably from 1 to 99 mass %, morepreferably from 1 to 40 mass % in the working medium (100 mass %). Whenthe content of the HFO is from 1 to 40 mass %, it is possible to providea heat cycle system excellent in the cycle performance (efficiency andcapacity), as compared with a working medium comprising HCFO-1224yd.

(Lubricating Oil)

As the lubricating oil to be used for the working medium-containingcomposition, a known lubricating oil used for the heat cycle system maybe used.

The lubricating oil may, for example, be an oxygen-containing syntheticoil (such as an ester lubricating oil or an ether lubricating oil), afluorinated lubricating oil, a mineral oil or a hydrocarbon syntheticoil.

The ester lubricating oil may, for example, be a dibasic acid ester oil,a polyol ester oil, a complex ester oil or a polyol carbonate oil.

The dibasic acid ester oil is preferably an ester of a C₅₋₁₀ dibasicacid (such as glutaric acid, adipic acid, pimelic acid, suberic acid,azelaic acid or sebacic acid) with a C₁₋₁₅ monohydric alcohol which islinear or has a branched alkyl group (such as methanol, ethanol,propanol, butanol, pentanol, hexanol, heptanol, octanol, nonanol,decanol, undecanol, dodecanol, tridecanol, tetradecanol orpentadecanol). Specifically, ditridecyl glutarate, di(2-ethylhexyl)adipate, diisodecyl adipate, ditridecyl adipate or di(3-ethylhexyl)sebacate may, for example, be mentioned.

The polyol ester oil is preferably an ester of a diol (such as ethyleneglycol, 1,3-propanediol, propylene glycol, 1,4-butanediol,1,2-butandiol, 1,5-pentadiol, neopentyl glycol, 1,7-heptanediol or1,12-dodecanediol) or a polyol having from 3 to 20 hydroxy groups (suchas trimethylolethane, trimethylolpropane, trimethylolbutane,pentaerythritol, glycerol, sorbitol, sorbitan or sorbitol/glycerincondensate) with a C₆₋₂₀ fatty acid (such as a linear or branched fattyacid such as hexanoic acid, heptanoic acid, octanoic acid, nonanoicacid, decanoic acid, undecanoic acid, dodecanoic acid, eicosanoic acidor oleic acid, or a so-called neo acid having a quaternary a carbonatom).

The polyol ester oil may have a free hydroxy group.

The polyol ester oil is preferably an ester (such as trimethylolpropanetripelargonate, pentaerythritol 2-ethylhexanoate or pentaerythritoltetrapelargonate) of a hindered alcohol (such as neopentyl glycol,trimethylolethane, trimethylolpropane, trimethylolbutane orpentaerythritol).

The complex ester oil is an ester of a fatty acid and a dibasic acid,with a monohydric alcohol and a polyol. The fatty acid, the dibasicacid, the monohydric alcohol and the polyol may be as defined above.

The polyol carbonate oil is an ester of carbonic acid with a polyol.

The polyol may be the above-described diol or the above-describedpolyol. Further, the polyol carbonate oil may be a ring-opening polymerof a cyclic alkylene carbonate.

The ether lubricating oil may be a polyvinyl ether oil or apolyoxyalkylene lubricating oil.

The polyvinyl ether oil may be one obtained by polymerizing a vinylether monomer such as an alkyl vinyl ether, or a copolymer obtained bycopolymerizing a vinyl ether monomer and a hydrocarbon monomer having anolefinic double bond.

The vinyl ether monomers may be used alone or in combination of two ormore.

The hydrocarbon monomer having an olefinic double bond may, for example,be ethylene, propylene, various forms of butene, various forms ofpentene, various forms of hexene, various forms of heptene, variousforms of octene, diisobutylene, triisobutylene, styrene, α-methylstyreneor alkyl-substituted styrene. The hydrocarbon monomers having anolefinic double bond may be used alone or in combination of two or more.

The polyvinyl ether copolymer may be either of a block copolymer and arandom copolymer.

The polyvinyl ethers may be used alone or in combination of two or more.

The polyoxyalkylene lubricating oil may, for example, be apolyoxyalkylene monool, a polyoxyalkylene polyol, an alkyl ether of apolyoxyalkylene monool or a polyoxyalkylene polyol, or an ester of apolyoxyalkylene monool or a polyoxyalkylene polyol. The polyoxyalkylenemonool or the polyoxyalkylene polyol may be one obtained by e.g. amethod of subjecting a C₂₋₄ alkylene oxide (such as ethylene oxide orpropylene oxide) to ring-opening addition polymerization to an initiatorsuch as water or a hydroxy group-containing compound in the presence ofa catalyst such as an alkali hydroxide. Further, one molecule of thepolyoxyalkylene chain may contain single oxyalkylene units or two ormore types of oxyalkylene units. It is preferred that at leastoxypropylene units are contained in one molecule.

The initiator may, for example, be water, a monohydric alcohol such asmethanol or butanol, or a polyhydric alcohol such as ethylene glycol,propylene glycol, pentaerythritol or glycerol.

The polyoxyalkylene lubricating oil is preferably an alkyl ether or anester of a polyoxyalkylene monool or polyoxyalkylene polyol. Further,the polyoxyalkylene polyol is preferably a polyoxyalkylene glycol.Particularly preferred is an alkyl ether of a polyoxyalkylene glycolhaving the terminal hydroxy group of the polyoxyalkylene glycol cappedwith an alkyl group such as a methyl group, which is called a polyglycoloil.

The fluorinated lubricating oil may, for example, be a compound havinghydrogen atoms of a synthetic oil (such as the after-mentioned mineraloil, poly-α-olefin, alkylbenzene or alkylnaphthalene) substituted byfluorine atoms, a perfluoropolyether oil or a fluorinated silicone oil.

The mineral oil may, for example, be a naphthene mineral oil or aparaffin mineral oil obtained by purifying a lubricating oil fractionobtained by atmospheric distillation or vacuum distillation of crude oilby a purification treatment (such as solvent deasphalting, solventextraction, hydrocracking, solvent dewaxing, catalytic dewaxing,hydrotreating or clay treatment) optionally in combination.

The hydrocarbon synthetic oil may, for example, be a poly-α-olefin, analkylbenzene or an alkylnaphthalene.

The lubricating oils may be used alone or in combination of two or more.

The content of the lubricating oil is not limited within a range not toremarkably decrease the effects of the present invention, variesdepending upon e.g. the application and the form of a compressor, and ispreferably from 10 to 100 parts by mass, more preferably from 20 to 50parts by mass based on the working medium (100 parts by mass).

(Stabilizer)

The stabilizer to be used for the working medium-containing compositionis a component which improves the stability of the working mediumagainst heat and oxidation.

The stabilizer may, for example, be an oxidation resistance-improvingagent, a heat resistance-improving agent or a metal deactivator.

The oxidation resistance-improving agent and the heatresistance-improving agent may, for example, beN,N′-diphenylphenylenediamine, p-octyldiphenylamine,p,p′-dioctyldiphenylamine, N-phenyl-1-naphthyamine,N-phenyl-2-naphthylamine, N-(p-dodecyl)phenyl-2-naphthylamine,di-1-naphthylamine, di-2-naphthylamine, N-alkylphenothiazine,6-(t-butyl)phenol, 2,6-di-(t-butyl)phenol,4-methyl-2,6-di-(t-butyl)phenol or4,4′-methylenebis(2,6-di-t-butylphenol). The oxidationresistance-improving agents and the heat resistance-improving agents maybe used alone or in combination of two or more.

The metal deactivator may, for example, be imidazole, benzimidazole,2-mercaptobenzothiazole, 2,5-dimercaptothiadiazole,salicylysine-propylenediamine, pyrazole, benzotriazole, tritriazole,2-methylbenzamidazole, 3,5-dimethylpyrazole, methylenebis-benzotriazole,an organic acid or an ester thereof, a primary, secondary or tertiaryaliphatic amine, an amine salt of an organic acid or inorganic acid, aheterocyclic nitrogen-containing compound, an amine salt of an alkylphosphate, or a derivative thereof.

The content of the stabilizer is not limited within a range not toremarkably decrease the effects of the present invention, and ispreferably at most 5 mass %, more preferably at most 1 mass % in theworking medium-containing composition (100 mass %).

(Leak Detecting Substance)

The leak detecting substance to be used for the workingmedium-containing composition may, for example, be an ultravioletfluorescent dye, an odor gas or an odor masking agent.

The ultraviolet fluorescent dye may be known ultraviolet fluorescentdyes as disclosed in e.g. U.S. Pat. No. 4,249,412, JP-A-10-502737,JP-A-2007-511645, JP-A-2008-500437 and JP-A-2008-531836.

The odor masking agent may be known perfumes as disclosed in e.g.JP-A-2008-500437 and JP-A-2008-531836.

In a case where the leak detecting substance is used, a solubilizingagent which improves the solubility of the leak detecting substance inthe working medium may be used.

The solubilizing agent may be ones as disclosed in e.g.JP-A-2007-511645, JP-A-2008-500437 and JP-A-2008-531836.

The content of the leak detecting substance is not particularly limitedwithin a range not to remarkably decrease the effects of the presentinvention, and is preferably at most 2 mass %, more preferably at most0.5 mass % in the working medium-containing composition (100 mass %).

(Other Compound)

The working medium of the present invention and the workingmedium-containing composition may contain a C₁₋₄ alcohol or a compoundused as a conventional working medium, coolant or heat transfer medium(hereinafter the alcohol and the compound will generally be referred toas other compound).

As such other compound, the following compounds may be mentioned.

Fluorinated ether: Perfluoropropyl methyl ether (C₃F₇OCH₃),perfluorobutyl methyl ether (C₄F₉OCH₃), perfluorobutyl ethyl ether(C₄F₉OC₂H₅), 1,1,2,2-tetrafluoroethyl-2,2,2-trifluoroethyl ether(CF₂HCF₂OC H₂C F₃, manufactured by Asahi Glass Company, Limited,AE-3000), etc.

The content of such other compound is not limited within a range not toremarkably decrease the effects of the present invention, and ispreferably at most 30 mass %, more preferably at most 20 mass %,particularly preferably at most 15 mass % in the workingmedium-containing composition (100 mass %).

<Heat Cycle System>

The heat cycle system of the present invention is a system employing theworking medium of the present invention.

The heat cycle system may, for example, be a Rankine cycle system, aheat pump cycle system, a refrigerating cycle system or a heat transportsystem.

(Refrigerating Cycle System)

As an example of the heat cycle system, a refrigerating cycle systemwill be described.

The refrigerating cycle system is a system wherein in an evaporator, aworking medium removes heat energy from a load fluid to cool the loadfluid thereby to accomplish cooling to a lower temperature.

FIG. 1 is a schematic construction view illustrating an example of arefrigerating cycle system of the present invention. A refrigeratingcycle system 10 is a system generally comprising a compressor 11 tocompress a working medium vapor A to form a high temperature/highpressure working medium vapor B, a condenser 12 to cool and liquefy theworking medium vapor B discharged from the compressor 11 to form a lowtemperature/high pressure working medium C, an expansion valve 13 to letthe working medium C discharged from the condenser 12 expand to form alow temperature/low pressure working medium D, an evaporator 14 to heatthe working medium D discharged from the expansion valve 13 to form ahigh temperature/low pressure working medium vapor A, a pump 15 tosupply a load fluid E to the evaporator 14, and a pump 16 to supply afluid F to the condenser 12.

In the refrigerating cyclic system 10, the following cycle is repeated.

(i) A working medium vapor A discharged from an evaporator 14 iscompressed by a compressor 11 to form a high temperature/high pressureworking medium vapor B.

(ii) The working medium vapor B discharged from the compressor 11 iscooled and liquefied by a fluid F in a condenser 12 to form a lowtemperature/high pressure working medium C. At that time, the fluid F isheated to form a fluid F′, which is discharged from the condenser 12.

(iii) The working medium C discharged from the condenser 12 is expandedin an expansion valve 13 to form a low temperature/low pressure workingmedium D.

(iv) The working medium D discharged from the expansion valve 13 isheated by a load fluid E in an evaporator 14 to form a hightemperature/low pressure working medium vapor A. At that time, the loadfluid E is cooled and becomes a load fluid E′, which is discharged fromthe evaporator 14.

The refrigerating cycle system 10 is a cycle comprising an adiabaticisentropic change, an isenthalpic change and an isobaric change, and thestate change of the working medium may be shown as in FIG. 2, when it isrepresented on a temperature-entropy chart.

In FIG. 2, the AB process is a process wherein adiabatic compression iscarried out by the compressor 11 to change the high temperature/lowpressure working medium vapor A to a high temperature/high pressureworking medium vapor B. The BC process is a process wherein isobariccooling is carried out in the condenser 12 to change the hightemperature/high pressure working medium vapor B to a lowtemperature/high pressure working medium C. The CD process is a processwherein isenthalpic expansion is carried out by the expansion valve 13to change the low temperature/high pressure working medium C to a lowtemperature/low pressure working medium D. The DA process is a processwherein isobaric heating is carried out in the evaporator 14 to have thelow temperature/low pressure working medium D returned to a hightemperature/low pressure working medium vapor A.

In the same manner, the state change of the working medium may be shownas in FIG. 3, when it is represented on a pressure-enthalpy chart.

(Moisture Concentration)

There is a problem of inclusion of moisture in the heat cycle system.Inclusion of moisture may cause freezing in a capillary tube, hydrolysisof the working medium or the lubricating oil, deterioration of materialsby an acid component formed in heat cycle, formation of contaminants,etc. Particularly, the above-described ether lubricating oil, esterlubricating oil and the like have extremely high moisture absorbingproperties and are likely to undergo hydrolysis, and inclusion ofmoisture decreases properties of the lubricating oil and may be a greatcause to impair the long term reliability of a compressor. Further, inan automobile air conditioner, moisture tends to be included from acoolant hose or a bearing of a compressor used for the purpose ofabsorbing vibration. Accordingly, in order to suppress hydrolysis of thelubricating oil, it is necessary to suppress the moisture concentrationin the heat cycle system. The moisture concentration of the workingmedium in the heat cycle system is preferably at most 100 ppm, morepreferably at most 20 ppm.

As a method of suppressing the moisture concentration in the heat cyclesystem, a method of using a desiccating agent (such as silica gel,activated aluminum or zeolite) may be mentioned. The desiccating agentis preferably a zeolite desiccating agent in view of chemical reactivityof the desiccating agent and the working medium, and the moistureabsorption capacity of the desiccating agent.

The zeolite desiccating agent is, in a case where a lubricating oilhaving a large moisture absorption as compared with a conventionalmineral lubricating oil is used, preferably a zeolite desiccating agentcontaining a compound represented by the following formula (1) as themain component in view of excellent moisture absorption capacity.M_(2/n)O·Al₂O₃ ·xSiO₂ ·yH₂O  (1)wherein M is a group 1 element such as Na or K or a group 2 element suchas Ca, n is the valence of M, and x and y are values determined by thecrystal structure. The pore size can be adjusted by changing M.

To select the desiccating agent, the pore size and the fracture strengthare important.

In a case where a desiccating agent having a pore size larger than themolecular size of the working medium is used, the working medium isadsorbed in the desiccating agent and as a result, chemical reactionbetween the working medium and the desiccating agent will occur, thusleading to undesired phenomena such as formation of non-condensing gas,a decrease in the strength of the desiccating agent, and a decrease inthe adsorption capacity.

Accordingly, it is preferred to use as the desiccating agent a zeolitedesiccating agent having a small pore size. Particularly preferred issodium/potassium type A synthetic zeolite having a pore size of at most3.5 Å. By using a sodium/potassium type A synthetic zeolite having apore size smaller than the molecular size of the working medium, it ispossible to selectively adsorb and remove only moisture in the heatcycle system without adsorbing the working medium. In other words, theworking medium is less likely to be adsorbed in the desiccating agent,whereby heat decomposition is less likely to occur and as a result,deterioration of materials constituting the heat cycle system andformation of contaminants can be suppressed.

The size of the zeolite desiccating agent is preferably from about 0.5to about 5 mm, since if it is too small, a valve or a thin portion inpipelines may be clogged, and if it is too large, the drying capacitywill be decreased. Its shape is preferably granular or cylindrical.

The zeolite desiccating agent may be formed into an optional shape bysolidifying powdery zeolite by a binding agent (such as bentonite). Solong as the desiccating agent is composed mainly of the zeolitedesiccating agent, other desiccating agent (such as silica gel oractivated alumina) may be used in combination.

The proportion of the zeolite desiccating agent based on the workingmedium is not particularly limited.

(Non-Condensing Gas Concentration)

If non-condensing gas is included in the heat cycle system, it hasadverse effects such as heat transfer failure in the condenser or theevaporator and an increase in the working pressure, and it is necessaryto suppress its inclusion as far as possible. Particularly, oxygen whichis one of non-condensing gases reacts with the working medium or thelubricating oil and promotes their decomposition.

The non-condensing gas concentration is preferably at most 1.5 vol %,particularly preferably at most 0.5 vol % by the volume ratio based onthe working medium, in a gaseous phase of the working medium.

EXAMPLES

Now, the present invention will be described in further detail withreference to Examples. However, it should be understood that the presentinvention is by no means restricted to such specific Examples.

(Evaluation of Refrigerating Cycle Performance)

The refrigerating cycle performance (the refrigerating capacity and thecoefficient of performance) was evaluated as the cycle performance (thecapacity and the efficiency) in a case where a working medium wasapplied to a refrigerating cycle system 10 shown in FIG. 1.

Evaluation was carried out by setting the average evaporationtemperature of the working medium in an evaporator 14, the averagecondensing temperature of the working medium in a condenser 12, thesupercooling degree of the working medium in the condenser 12, and thedegree of superheat of the working medium in the evaporator 14,respectively. Further, it was assumed that there was no pressure loss inthe equipment efficiency and in the pipelines and heat exchanger.

The refrigerating capacity Q and the coefficient of performance η areobtained from the following formulae (2) and (3) using the enthalpy h ineach state (provided that a suffix attached to h indicates the state ofthe working medium).Q=h _(A) −h _(D)  (2)η=refrigerating capacity/compression work=(h _(A) −h _(D))/(h _(B) −h_(A))  (3)

The coefficient of performance means the efficiency in the refrigeratingcycle system, and a higher coefficient of performance means that ahigher output (refrigerating capacity) can be obtained by a smallerinput (electric energy required to operate a compressor).

Further, the refrigerating capacity means a capacity to cool a loadfluid, and a higher refrigerating capacity means that more works can bedone in the same system. In other words, it means that with a workingmedium having a larger refrigerating capacity, the desired performancecan be obtained with a smaller amount, whereby the system can bedownsized.

The thermodynamic properties required for calculation of therefrigerating cycle performance were calculated based on the generalizedequation of state (Soave-Redlich-Kwong equation) based on the law ofcorresponding state and various thermodynamic equations. If acharacteristic value was not available, it was calculated employing anestimation technique based on a group contribution method.

Example 1

The refrigerating cycler performance (the refrigerating capacity and thecoefficient of performance) was evaluated in a case where HCFO-1224yd,1,1-dichloro-2,2,2-trifluoroethane (HCFC-123),1,1,1,3,3-pentafluoropropane (HFC-245fa) or HFC-134a as a working mediumwas applied to a refrigerating cycle system 10 shown in FIG. 1.

The evaporation temperature of the working medium in an evaporator 14,the condensing temperature of the working medium in a condenser 12, thesupercooling degree of the working medium in the condenser 12 and thedegree of superheat of the working medium in the evaporator 14 weretemperatures as identified in Table 1.

Based on the refrigerating cycle performance of HFC-245fa, the relativeperformance (each working medium/HFC-245fa) of the refrigerating cycleperformance (the refrigerating capacity and the coefficient ofperformance) of each working medium based on HFC-245fa was obtained. Theresults of each working medium are shown in Table 1.

TABLE 1 Degree Relative performance (based on HFC-245fa) [—] of Super-HCFO-1224yd HCFC-123 HFC-245fa HFC-134a Evaporation Condensing super-cooling Coefficient Refrig- Coefficient Refrig- Coefficient Refrig-Coefficient temperature temperature heat degree of erating of erating oferating of Refrigerating [° C.] [° C.] [° C.] [° C.] performancecapacity performance capacity performance capacity performance capacity0 50 5 5 0.997 1.473 1.038 0.643 1.000 1.000 0.939 4.124 10 60 5 5 0.9961.414 1.044 0.651 1.000 1.000 0.917 3.707 20 70 5 5 0.995 1.362 1.0510.660 1.000 1.000 0.886 3.324 30 80 5 5 0.994 1.317 1.060 0.670 1.0001.000 0.841 2.952

From the results in Table 1, it was confirmed that HCFO-1224yd had ahigh refrigerating capacity as compared with HFC-245fa, and had nodistinct difference in the coefficient of performance.

Example 2

The refrigerating cycle performance (the refrigerating capacity and thecoefficient of performance) was evaluated in a case where a workingmedium comprising HCFO-1224yd and a HFO as identified in Table 2 wasapplied to a refrigerating cycle system 10 shown in FIG. 1.

Evaluation was carried out by setting the average evaporationtemperature of the working medium in an evaporator 14 to be 0° C., theaverage condensing temperature of the working medium in a condenser 12to be 50° C., the supercooling degree of the working medium in thecondenser 12 to be 5° C., and the degree of superheat of the workingmedium in the evaporator 14 to be 5° C.

Based on the refrigerating cycle performance of HFC-245fa, the relativeperformance (each working medium/HFC-245fa) of the refrigerating cycleperformance (the refrigerating capacity and the coefficient ofperformance) of each working medium based on HFC-245fa was obtained. Theresults of each working medium are shown in Table 2.

TABLE 2 Relative Relative Relative performance performance performance(based on HFC- (based on HFC- (based on HFC- 245fa) [—] 245fa) [—]245fa) [—] HFO- HCFO- Coefficient Refrig- HFO- HCFO- Coefficient Refrig-HFO- HCFO- Coefficient 1132(Z) 1224yd of erating 1132(E) 1224yd oferating 1123 1224yd of Refrigerating [mass %] [mass %] performancecapacity [mass %] [mass %] performance capacity [mass %] [mass %]performance capacity 0 100 0.997 1.473 0 100 0.997 1.473 0 100 0.9971.473 20 80 0.997 2.631 20 80 0.994 2.610 20 80 0.980 2.874 40 60 0.9793.558 40 60 0.977 3.516 40 60 0.967 4.302 60 40 0.960 4.354 60 40 0.9594.283 60 40 0.902 5.515 80 20 0.958 5.121 80 20 0.958 5.012 80 20 0.8476.873 90 10 0.959 5.459 90 10 0.960 5.331 90 10 0.839 7.714 92 8 0.9585.520 92 8 0.960 5.389 92 8 0.838 7.886 94 6 0.958 5.580 94 6 0.9605.445 94 6 0.838 8.056 96 4 0.958 5.637 96 4 0.960 5.499 96 4 0.8378.222 98 2 0.958 5.692 98 2 0.960 5.551 98 2 0.836 8.382 100 0 0.9575.746 100 0 0.960 5.601 100 0 0.834 8.536

From the results in Table 2, it was confirmed that the refrigeratingcapacity of HCFO-1224yd could be improved without a remarkable decreaseof the coefficient of performance by adding a HFO to HCFO-1224yd.

Example 3

The refrigerating cycle performance (the refrigerating capacity and thecoefficient of performance) was evaluated in a case where a workingmedium comprising HCFO-1224yd and a HCFC or a HFC as identified in Table3 or 4 was applied to a refrigerating cycle system 10 shown in FIG. 1.

Evaluation was carried out by setting the average evaporationtemperature of the working medium in an evaporator 14 to be 0° C., theaverage condensing temperature of the working medium in a condenser 12to be 50° C., the supercooling degree of the working medium in thecondenser 12 to be 5° C., and the degree of superheat of the workingmedium in the evaporator 14 to be 5° C.

Based on the refrigerating cycle performance of HFC-245fa, the relativeperformance (each working medium/HFC-245fa) of the refrigerating cycleperformance (the refrigerating capacity and the coefficient ofperformance) of each working medium based on HFC-245fa was obtained. Theresults of each working medium are shown in Tables 3 and 4.

TABLE 3 Relative Relative Relative performance performance performance(based on HFC- (based on HFC- (based on HFC- 245fa) [—] 245fa) [—]245fa) [—] HCFO- HFC- Coefficient Refrig- HCFO- HFC- Coefficient Refrig-HCFO- HFC- Coefficient 1224yd 134a of erating 1224yd 245fa of erating1224yd 125 of Refrigerating [mass %] [mass %] performance capacity [mass%] [mass %] performance capacity [mass %] [mass %] performance capacity0 100 0.939 4.124 0 100 1.000 1.000 0 100 0.746 6.255 20 80 0.947 3.72620 80 0.835 1.410 20 80 0.825 5.253 40 60 0.959 3.225 40 60 0.986 1.53440 60 0.910 4.299 60 40 0.978 2.697 60 40 1.022 1.611 60 40 0.964 3.34780 20 0.988 2.113 80 20 1.020 1.597 80 20 0.982 2.347 100 0 0.997 1.473100 0 0.997 1.473 100 0 0.997 1.473

TABLE 4 Relative performance Relative performance HCFO- (based onHFC-245fa) [—] HCFO- HFC- (based on HFC-245fa) [—] 1224yd HFC-32Coefficient of Refrigerating 1224yd 152a Coefficient of Refrigerating[mass %] [mass %] performance capacity [mass %] [mass %] performancecapacity 0 100 0.862 10.387 0 100 0.981 3.937 20 80 0.878 7.886 20 800.985 3.543 40 60 0.933 6.290 40 60 0.991 3.118 60 40 0.981 4.729 60 400.997 2.648 80 20 1.003 3.079 80 20 1.000 2.107 90 10 0.997 2.243 90 100.998 1.801 92 8 0.996 2.081 92 8 0.998 1.737 94 6 0.994 1.922 94 60.997 1.672 96 4 0.993 1.767 96 4 0.997 1.607 98 2 0.994 1.617 98 21.015 1.540 100 0 0.997 1.473 100 0 0.997 1.473

From the results in Tables 3 and 4, it was confirmed that therefrigerating capacity of HCFO-1224yd could be improved by adding a HFCto HCFO-1224yd.

Example 4

The refrigerating cycle performance (the refrigerating capacity and thecoefficient of performance) was evaluated in a case where a workingmedium comprising HCFO-1224yd and a hydrocarbon as identified in Table 5was applied to a refrigerating cycle system 10 shown in FIG. 1.

Evaluation was carried out by setting the average evaporationtemperature of the working medium in an evaporator 14 to be 0° C., theaverage condensing temperature of the working medium in a condenser 12to be 50° C., the supercooling degree of the working medium in thecondenser 12 to be 5° C., and the degree of superheat of the workingmedium in the evaporator 14 to be 5° C.

Based on the refrigerating cycle performance of HFC-245fa, the relativeperformance (each working medium/HFC-245fa) of the refrigerating cycleperformance (the refrigerating capacity and the coefficient ofperformance) of each working medium based on HFC-245fa was obtained. Theresults of each working medium are shown in Table 5.

TABLE 5 Relative Relative Relative performance performance performance(based on HFC- (based on HFC- (based on HFC- 245fa) [—] 245fa) [—]245fa) [—] HCFO- Coefficient Refrig- HCFO- Coefficient Refrig- HCFO-Coefficient 1224yd Butane of erating 1224yd Isobutane of erating 1224ydPropane of Refrigerating [mass %] [mass %] performance capacity [mass %][mass %] performance capacity [mass %] [mass %] performance capacity 0100 1.000 1.621 0 100 0.975 2.229 0 100 0.917 5.528 20 80 1.094 1.639 2080 0.990 2.196 20 80 0.919 5.062 40 60 0.934 1.654 40 60 0.991 2.137 4060 0.926 4.484 60 40 — — 60 40 0.991 2.031 60 40 0.948 3.792 80 20 1.0141.617 80 20 1.007 1.840 80 20 0.976 2.868 90 10 1.012 1.566 90 10 0.9941.688 90 10 0.981 2.229 92 8 1.019 1.552 92 8 0.997 1.651 92 8 0.9812.085 94 6 1.025 1.535 94 6 1.001 1.611 94 6 0.981 1.936 96 4 1.0211.517 96 4 1.006 1.569 96 4 0.983 1.783 98 2 1.032 1.497 98 2 1.0171.523 98 2 1.016 1.629 100 0 0.997 1.473 100 0 0.997 1.473 100 0 0.9971.473

From the results in Table 5, it was confirmed that the refrigeratingcapacity of HCFO-1224yd could be improved without a remarkable decreaseof the coefficient of performance by adding a hydrocarbon toHCFO-1224yd.

Example 5

The refrigerating cycle performance (the refrigerating capacity and thecoefficient of performance) was evaluated in a case where HCFO-1224yd,HCFC-123 or HCFO-1233zd(E) as a working medium was applied to arefrigerating cycle system 10 shown in FIG. 1.

Evaluation was carried out by setting the average evaporationtemperature of the working medium in an evaporator 14 to be from −10 to+50° C., the average condensing temperature of the working medium in acondenser 12 to be the average evaporation temperature +50° C., thesupercooling degree of the working medium in the condenser 12 to be 5°C., and the degree of superheat of the working medium in the evaporator14 to be 5° C.

Based on the refrigerating cycle performance of HCFC-123, the relativeperformance (each working medium/HCFC-123) of the refrigerating cycleperformance (the refrigerating capacity and the coefficient ofperformance) of each working medium based on HCFC-123 was obtained. Theresults of each working medium are shown in Table 6.

TABLE 6 Relative performance (based on HCFC-123) [—] Refrigeratingcapacity Coefficient of performance HCFO-1224yd 1.78-2.42 0.91-0.97HCFC-123 1 1 HCFO-1233zd(E) 1.27-1.47 0.98-1.00

From the results in Table 6, it was confirmed that HCFO-1224yd had ahigh refrigerating capacity as compared with HCFO-1233zd(E), and had nodistinct difference in the coefficient of performance.

INDUSTRIAL APPLICABILITY

The working medium of the present invention is useful as a workingmedium for heat cycle such as a coolant for a refrigerator, a coolantfor an air conditioner, a working fluid for power generation system(such as exhaust heat recovery power generation), a working medium for alatent heat transport apparatus (such as a heat pipe) or a secondarycooling medium.

This application is a continuation of PCT Application No.PCT/JP2012/062842, filed on May 18, 2012, which is based upon and claimsthe benefit of priority from Japanese Patent Application No. 2011-112415filed on May 19, 2011. The contents of those applications areincorporated herein by reference in its entirety.

REFERENCE SYMBOL

-   10: Refrigerating cycle system

What is claimed is:
 1. A working medium composition, which comprises amineral oil; and a working medium comprising1-chloro-2,3,3,3-tetrafluoropropene in a content of at least 60 mass %based on 100 mass % of the working medium and if the working mediumcomprises less than 100 mass % of the1-chloro-2,3,3,3-tetrafluoropropene, the working medium comprises one ormore selected from the group consisting of difluoromethane (HFC-32),1,1-difluoroethane (HFC-152a), 1,1,2,2-tetrafluoroethane (HFC-134),1,1,1,2-tetrafluoroethane (HFC-134a), pentafluoroethane (HFC-125),1,1-difluoroethylene (HFO-1132a), 1,2-difluoroethylene (HFO-1132),1,1,2-trifluoroethylene (HFO-1123), 1,1,1,3,3-pentafluoropropane(HFC-245fa) and a 1,1-dichloro-2,2,2-trifluoroethane (HCFC-123) so thatthe total including the 1-chloro-2,3,3,3-tetrafluoropropene is 100 mass% of the working medium.
 2. The working medium composition according toclaim 1, wherein the mineral oil is present in a content of 10-100 partsby mass based on the working medium (100 parts by mass).
 3. The workingmedium composition according to claim 1, wherein the mineral oil ispresent in a content of 20-50 parts by mass based on the working medium(100 parts by mass).
 4. The working medium composition according toclaim 1, wherein the mineral oil is a naphthene mineral oil.
 5. Theworking medium composition according to claim 1, wherein the mineral oilis a paraffin mineral oil.
 6. The working medium composition accordingto claim 1, wherein the mineral oil is a purified fraction obtained byatmospheric distillation or vacuum distillation of crude oil.